Safety critical control system that includes control logic or machine readable instructions that selectively locks or enables the control system based on one or more machine implemented state machines that includes states associated with detection or matching of one or more predetermined signals on distinct conduction paths between elements of the control system and related methods

This disclosure involves a method of controlling a safety critical control device, the method comprising: sending user inputs to a first state machine, identifying user inputs by the first state machine, determining the correct state to communicate to a second state machine, the correct state being determined by selecting one state of a plurality of states depending on the user inputs, communicating the correct state to a second state machine through a control bus, and determining the correct state for the second state machine based on communication from the control bus.